This invention relates to an apparatus for treating a web of material, and more particularly, relates to an apparatus for improving the surface of a web of material for coating or printing.
In the manufacture of material for printing, many different qualities of printing material are desired by the printing companies. In order to upgrade certain types of printing material to a smooth, glossy appearance, it is generally customary to take a web of rough, dull appearing material and subject the material to a plurality of pairs of pressure rolls. The pairs of pressure rolls are generally mounted so that each pair of rollers are adapted to receive a web of material therebetween, and pressing against each other, smooth out the rough portions of the material. Furthermore, the web of material is fed at a predetermined rate through the rollers and the rollers are adapted to rotate in the same direction as the moving web of material and at about the same rate of speed. Also, in some systems, steam means are utilized to moisten the printing material prior to entrance into the pressure rolling portion of the system in order to enhance the glossy appearance of the printing surface. However, it has been found that the aforementioned method of improving the printing surface of printing materials has proved to be expensive. Furthermore, an even better product, from a smoothness and appearance point of view, has been sought by the printing industry.